You probably don't have any plans to do anything further with league totals, but I strongly recommend that you read
this section of the OOTP 21 manual on league total modifiers. Checking that box and letting the game handle things is definitely the way to go. Never edit league totals or recalculate them. If you ever decide you want to change anything, only adjust the modifiers. The manual explains why this is so important and how it works.